Backlight not working on Samsung ATIV 8 laptop

[Laszlo KREKACS]

I have a 15" Samsung ATIV Book 8 laptop, np870z5e model from 2013.
It features an Intel core-i7 cpu, and integrated Intel Hd4000 video card and also an ATI Radeon video card.

According to Backlight debugging page[1], my case is
"Backlight control does not work, but there are entries in /sys/class/backlight. "

What works:
Fn-F2, Fn-F3 keys works(Brightness down, brightness up),
shows the brightness notification dialog, and also the
/sys/class/backlight/intel_backlight/actual_brightness file changes too.
It has no physical effect.

It does not have any physical effect (brightness does not change),
up until the brightness notification is zero (no bar on it), then the display switches off.
raising the brightness switches the display back to the same brightness it was,
and still not have any effect to the brightness.

Semi works:
Powering on the laptop starts with about 60% brightness.
If I suspend-resume the laptop, it results 100% brightness.
If I unplug the power cord (if it was plugged in when the laptop started), then it results 100% brightness.
If I plug the power cord (if it was unplugged when the laptop started), then it results 100% brightness.

I can't change the 100% brightness afterwards.

What I have tried:
a) xorg.conf file:

# Fix Backlight issue
Section "Device"
 Identifier "card0"
 Driver "intel"
 Option "Backlight" "intel_backlight"
 BusID "PCI:0:2:0"
EndSection

No effect.

b) Kernel boot parameter in /etc/defaults/grub
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video.use_native_backlight=1"
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video.use_native_backlight=0"
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=vendor"
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video.use_bios_initial_backlight=0"

I tried each one, with a power off - power on cycle, but none of it had any effect.
I doublechecked it (after boot), with cat /proc/cmdline.

Changing the /sys/class/backlight/intel_backlight/brightness values,
has no physical effect, although the file do change (checked with cat).

I'm desperately trying to solve this issue, because the screen is always at full brightness,
and burns my eyes out. (300cd/m2 screen is extremely bright).

Any help is much appreciated.

[1]: https://wiki.ubuntu.com/Kernel/Debugging/Backlight

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: linux-image-3.16.0-21-generic 3.16.0-21.28
ProcVersionSignature: Ubuntu 3.16.0-21.28-generic 3.16.4
Uname: Linux 3.16.0-21-generic x86_64
ApportVersion: 2.14.7-0ubuntu5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: lama 2528 F.... pulseaudio
CurrentDesktop: Unity
Date: Tue Oct 14 00:38:17 2014
InstallationDate: Installed on 2014-01-13 (273 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
MachineType: SAMSUNG ELECTRONICS CO., LTD. 870Z5E/880Z5E/680Z5E
ProcFB:
 0 inteldrmfb
 1 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.16.0-21-generic.efi.signed root=UUID=ba121a25-b094-49f5-96bf-ade769938060 ro quiet splash video.use_bios_initial_backlight=0 vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.16.0-21-generic N/A
 linux-backports-modules-3.16.0-21-generic N/A
 linux-firmware 1.135
SourcePackage: linux
UpgradeStatus: Upgraded to utopic on 2014-10-08 (5 days ago)
dmi.bios.date: 06/04/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P02ADH.008.130604.SK
dmi.board.asset.tag: No Asset Tag
dmi.board.name: NP870Z5E-X01HU
dmi.board.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.board.version: SEC_SW_REVISION_1234567890ABCD
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 9
dmi.chassis.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP02ADH.008.130604.SK:bd06/04/2013:svnSAMSUNGELECTRONICSCO.,LTD.:pn870Z5E/880Z5E/680Z5E:pvrP02ADH:rvnSAMSUNGELECTRONICSCO.,LTD.:rnNP870Z5E-X01HU:rvrSEC_SW_REVISION_1234567890ABCD:cvnSAMSUNGELECTRONICSCO.,LTD.:ct9:cvrN/A:
dmi.product.name: 870Z5E/880Z5E/680Z5E
dmi.product.version: P02ADH
dmi.sys.vendor: SAMSUNG ELECTRONICS CO., LTD.

[Laszlo KREKACS (laszlo-krekacs-list)]

sudo lspci -vnvn > lspci-vnvn.log
added.

[Laszlo KREKACS (laszlo-krekacs-list)]

$ ls /sys/class/backlight
intel_backlight

$ grep -r . /proc/acpi > acpi
/proc/acpi/button/lid/LID0/state:state: open
/proc/acpi/wakeup:Device S-state Status Sysfs node
/proc/acpi/wakeup:P0P1 S4 *disabled
/proc/acpi/wakeup:USB1 S3 *disabled
/proc/acpi/wakeup:USB2 S3 *disabled
/proc/acpi/wakeup:USB3 S3 *disabled
/proc/acpi/wakeup:USB4 S3 *disabled
/proc/acpi/wakeup:USB5 S3 *disabled
/proc/acpi/wakeup:USB6 S3 *disabled
/proc/acpi/wakeup:USB7 S3 *disabled
/proc/acpi/wakeup:RP01 S4 *disabled pci:0000:00:1c.0
/proc/acpi/wakeup:RP04 S4 *disabled pci:0000:00:1c.3
/proc/acpi/wakeup:PEG0 S4 *disabled pci:0000:00:01.0
/proc/acpi/wakeup:PEGP S4 *disabled pci:0000:01:00.0
/proc/acpi/wakeup:PEGA S4 *disabled
/proc/acpi/wakeup:PEG1 S4 *disabled
/proc/acpi/wakeup:PEG2 S4 *disabled
/proc/acpi/wakeup:PEG3 S4 *disabled
/proc/acpi/wakeup:PWRB S5 *enabled platform:PNP0C0C:00

[Laszlo KREKACS (laszlo-krekacs-list)]

sudo acpidump -o acpidump.txt

[Laszlo KREKACS (laszlo-krekacs-list)]

acpixtract acpidump.txt

[Laszlo KREKACS (laszlo-krekacs-list)]

sudo fwts > fwts

[Laszlo KREKACS (laszlo-krekacs-list)]

results.log of 'sudo fwts > fwts' command

[Laszlo KREKACS (laszlo-krekacs-list)]

sudo fwts > fwts
sudo fwts method > fwts_method

[Laszlo KREKACS (laszlo-krekacs-list)]

dmesg | grep 'ACPI: Video' > video

[Laszlo KREKACS (laszlo-krekacs-list)]

sudo dmidecode > dmidecode.log

[Laszlo KREKACS (laszlo-krekacs-list)]

$ cat /proc/version
Linux version 3.16.0-21-generic (buildd@panlong) (gcc version 4.9.1 (Ubuntu 4.9.1-16ubuntu4) ) #28-Ubuntu SMP Mon Oct 6 16:00:43 UTC 2014

[Laszlo KREKACS (laszlo-krekacs-list)]

$ sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date
P02ADH.008.130604.SK
06/04/2013

[Brad Figg (brad-figg)]

This change was made by a bot.

[Laszlo KREKACS (laszlo-krekacs-list)]

Possible upstream bug:
https://bugzilla.kernel.org/show_bug.cgi?id=84561

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.18 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.18-rc1-utopic/

[Peter Ries (peterriesde)]

Same effect on my Samsung Ativ Book 7 (intel i7 intel/ati hybrid) neither radeon, nor fglrx is working. Kernels 3.13.0-37, 3.16.0-23/24 don't work. Everything worked unter Xubuntu 14.04 (under 14.04 acpi_backlight=vendor even turned on brightness sensor) Under 14.10 ONLY brightness sensor works and cannot be turned off. Brightnesse keys tell me they are working by notification bubbles but screen stays at 100%. xbacklight does not decrease brightess although it tells me it it running at 50% (screen still 100%)

[daniel fischer (danielfm123)]

same problem here on ativ book 8 2013......

[daniel fischer (danielfm123)]

tried upstream kernel and doesnt work

[daniel fischer (danielfm123)]

if i add GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Windows" on grub the grightness will start on midle (50%)
then if i plug or un plug the prowe source it will go 100%

[madbiologist (me-again)]

This should be fixed in the upstream 3.19 kernel by this patch

author Aaron Lu
committer Rafael J. Wysocki
commit 7d0b93499f4879ddbc75d594f4ea216ba964f78e (patch)
tree 7c65587b844e6709d4301599e67505c9335de1cb
parent 97bf6af1f928216fd6c5a66e8a57bfa95a659672 (diff)

ACPI / video: Add some Samsung models to disable_native_backlight list

Several Samsung laptop models (SAMSUNG 870Z5E/880Z5E/680Z5E and SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V) do not have a working native backlight control interface so restore their acpi_videoX interface.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=84221
Link: https://bugzilla.kernel.org/show_bug.cgi?id=84651
For SAMSUNG 870Z5E/880Z5E/680Z5E:
Reported-and-tested-by: Brent Saner
Reported-by: Vitaliy Filippov
Reported-by: Laszlo KREKACS
For SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V:
Reported-by: Vladimir Perepechin
Cc: 3.17+ <email address hidden> # 3.17+
Signed-off-by: Aaron Lu
Signed-off-by: Rafael J. Wysocki

A PPA of the 3.19-rc3 kernel is available at http://kernel.ubuntu.com/~kernel-ppa/mainline/ and instructions on how to install and uninstall it are available at https://wiki.ubuntu.com/Kernel/MainlineBuilds

[Giuseppe Scoppino (scoppino-giuseppe)]

Brightness still not working on the Samsung 780Z5E, I'd also suspect 770Z5E as well. There are no hardware differences between the 780Z5E and 880Z5E so it's probably just a case of adding these to disable_native_backlight as well.

[Stefan Burnicki (stefan-burnicki)]

Brightness control also does not work on Samsung 730U3E.

I'm running 15.04 with 3.19.0-15 kernel and having the same symptoms as reported and none of the listed kernel boot parameters show any effect.

[madbiologist (me-again)]

Giuseppe Scoppino and Stefan Burnicki - as you have different hardware than the original reporter, you should file new bug reports. However, it would probably be more productive to skip that step and file upstream bug reports at https://bugzilla.kernel.org/

[Michael Murphy (mmstick)]

I always find that setting acpi_backlight=None in /etc/default/grub and then running sudo update-grub && sudo reboot will fix this problem with Intel-based laptops quite easily.

[Bruno (brvollino)]

I've found a solution for my case after a few days of despair.

It consists in using these options in /etc/default/grub:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=Linux acpi_backlight=video"

I have a Samsung laptop model NP470R4E running Ubuntu 16.10.